/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | foam-extend: Open Source CFD
   \\    /   O peration     | Version:     4.1
    \\  /    A nd           | Web:         http://www.foam-extend.org
     \\/     M anipulation  | For copyright notice see file Copyright
-------------------------------------------------------------------------------
License
	This file is part of foam-extend.

	foam-extend is free software: you can redistribute it and/or modify it
	under the terms of the GNU General Public License as published by the
	Free Software Foundation, either version 3 of the License, or (at your
	option) any later version.

	foam-extend is distributed in the hope that it will be useful, but
	WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
	General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with foam-extend.  If not, see <http://www.gnu.org/licenses/>.

\*---------------------------------------------------------------------------*/

#include "codeStream.H"
#include "addToMemberFunctionSelectionTable.H"
#include "IStringStream.H"
#include "OStringStream.H"
#include "dynamicCode.H"
#include "dynamicCodeContext.H"
#include "foamTime.H"
#include "PstreamReduceOps.H"

// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //

namespace Foam
{
namespace functionEntries
{
	defineTypeNameAndDebug(codeStream, 0);

	addToMemberFunctionSelectionTable
	(
		functionEntry,
		codeStream,
		execute,
		dictionaryIstream
	);

	addToMemberFunctionSelectionTable
	(
		functionEntry,
		codeStream,
		execute,
		primitiveEntryIstream
	);

}
}


const Foam::word Foam::functionEntries::codeStream::codeTemplateC
	= "codeStreamTemplate.C";


// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //

Foam::dlLibraryTable& Foam::functionEntries::codeStream::libs
(
	const dictionary& dict
)
{
	const IOdictionary& d = static_cast<const IOdictionary&>(dict.topDict());
	return const_cast<Time&>(d.time()).libs();
}


Foam::functionEntries::codeStream::streamingFunctionType
Foam::functionEntries::codeStream::getFunction
(
	const dictionary& parentDict,
	const dictionary& codeDict
)
{
	// get code, codeInclude, codeOptions
	dynamicCodeContext context(codeDict);

	// codeName: codeStream + _<sha1>
	// codeDir : _<sha1>
	std::string sha1Str(context.sha1().str(true));
	dynamicCode dynCode("codeStream" + sha1Str, sha1Str);

	// Load library if not already loaded
	// Version information is encoded in the libPath (encoded with the SHA1)
	const fileName libPath = dynCode.libPath();

	// see if library is loaded
	void* lib = nullptr;
	if (isA<IOdictionary>(parentDict.topDict()))
	{
		lib = libs(parentDict).findLibrary(libPath);
	}

	if (!lib)
	{
		Info<< "Using #codeStream with " << libPath << endl;
	}


	// nothing loaded
	// avoid compilation if possible by loading an existing library
	if (!lib)
	{
		if (isA<IOdictionary>(parentDict.topDict()))
		{
			// Cached access to dl libs. Guarantees clean up upon destruction
			// of Time.
			dlLibraryTable& dlLibs = libs(parentDict);
			if (dlLibs.open(libPath, false))
			{
				lib = dlLibs.findLibrary(libPath);
			}
		}
		else
		{
			// Uncached opening of libPath. Do not complain if cannot be loaded
			lib = dlOpen(libPath, false);
		}
	}


	// create library if required
	if (!lib)
	{
		bool create =
			Pstream::master()
		 || (regIOobject::fileModificationSkew() <= 0);   // not NFS

		if (create)
		{
			if (!dynCode.upToDate(context))
			{
				// filter with this context
				dynCode.reset(context);

				// compile filtered C template
				dynCode.addCompileFile(codeTemplateC);

				// define Make/options
				dynCode.setMakeOptions
				(
					"EXE_INC = -g \\\n"
				  + context.options()
				  + "\n\nLIB_LIBS = \\\n"
				  + "    -lfoam \\\n"
				  + context.libs()
				);

				if (!dynCode.copyOrCreateFiles(true))
				{
					FatalIOErrorIn
					(
					    "functionEntries::codeStream::execute(..)",
					    parentDict
					)   << "Failed writing files for" << nl
					    << dynCode.libRelPath() << nl
					    << exit(FatalIOError);
				}
			}

			if (!dynCode.wmakeLibso())
			{
				FatalIOErrorIn
				(
					"functionEntries::codeStream::execute(..)",
					parentDict
				)   << "Failed wmake " << dynCode.libRelPath() << nl
					<< exit(FatalIOError);
			}
		}

		//- Only block if we're not doing master-only reading. (flag set by
		//  regIOobject::read, IOdictionary constructor)
		if
		(
		   !regIOobject::masterOnlyReading
		&& regIOobject::fileModificationSkew() > 0
		)
		{
			//- Since the library has only been compiled on the master the
			//  other nodes need to pick this library up through NFS
			//  We do this by just polling a few times using the
			//  fileModificationSkew.

			off_t mySize = Foam::fileSize(libPath);
			off_t masterSize = mySize;
			Pstream::scatter(masterSize);

			if (debug)
			{
				Pout<< endl<< "on processor " << Pstream::myProcNo()
					<< " have masterSize:" << masterSize
					<< " and localSize:" << mySize
					<< endl;
			}


			if (mySize < masterSize)
			{
				if (debug)
				{
					Pout<< "Local file " << libPath
					    << " not of same size (" << mySize
					    << ") as master ("
					    << masterSize << "). Waiting for "
					    << regIOobject::fileModificationSkew
					    << " seconds." << endl;
				}
				Foam::sleep(regIOobject::fileModificationSkew());

				// Recheck local size
				mySize = Foam::fileSize(libPath);

				if (mySize < masterSize)
				{
					FatalIOErrorIn
					(
					    "functionEntries::codeStream::execute(..)",
					    parentDict
					)   << "Cannot read (NFS mounted) library " << nl
					    << libPath << nl
					    << "on processor " << Pstream::myProcNo()
					    << " detected size " << mySize
					    << " whereas master size is " << masterSize
					    << " bytes." << nl
					    << "If your case is not NFS mounted"
					    << " (so distributed) set fileModificationSkew"
					    << " to 0"
					    << exit(FatalIOError);
				}
			}

			if (debug)
			{
				Pout<< endl<< "on processor " << Pstream::myProcNo()
					<< " after waiting: have masterSize:" << masterSize
					<< " and localSize:" << mySize
					<< endl;
			}
		}

		if (isA<IOdictionary>(parentDict.topDict()))
		{
			// Cached access to dl libs. Guarantees clean up upon destruction
			// of Time.
			dlLibraryTable& dlLibs = libs(parentDict);

			if (debug)
			{
				Pout<< "Opening cached dictionary:" << libPath << endl;
			}

			if (!dlLibs.open(libPath, false))
			{
				FatalIOErrorIn
				(
					"functionEntries::codeStream::execute(..)",
					parentDict
				)   << "Failed loading library " << libPath << nl
					<< "Did you add all libraries to the 'libs' entry"
					<< " in system/controlDict?"
					<< exit(FatalIOError);
			}

			lib = dlLibs.findLibrary(libPath);
		}
		else
		{
			// Uncached opening of libPath
			if (debug)
			{
				Pout<< "Opening uncached dictionary:" << libPath << endl;
			}
			lib = dlOpen(libPath, true);
		}
	}

	bool haveLib = lib;
	if (!regIOobject::masterOnlyReading)
	{
		reduce(haveLib, andOp<bool>());
	}

	if (!haveLib)
	{
		FatalIOErrorIn
		(
			"functionEntries::codeStream::execute(..)",
			parentDict
		)   << "Failed loading library " << libPath
			<< " on some processors."
			<< exit(FatalIOError);
	}


	// Find the function handle in the library
	streamingFunctionType function =
		reinterpret_cast<streamingFunctionType>
		(
			dlSym(lib, dynCode.codeName())
		);


	if (!function)
	{
		FatalIOErrorIn
		(
			"functionEntries::codeStream::execute(..)",
			parentDict
		)   << "Failed looking up symbol " << dynCode.codeName()
			<< " in library " << lib << exit(FatalIOError);
	}

	return function;
}


// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //

bool Foam::functionEntries::codeStream::execute
(
	const dictionary& parentDict,
	primitiveEntry& entry,
	Istream& is
)
{
	Info<< "Using #codeStream at line " << is.lineNumber()
		<< " in file " <<  parentDict.name() << endl;

	dynamicCode::checkSecurity
	(
		"functionEntries::codeStream::execute(..)",
		parentDict
	);

	// get code dictionary
	// must reference parent for stringOps::expand to work nicely
	dictionary codeDict("#codeStream", parentDict, is);

	streamingFunctionType function = getFunction(parentDict, codeDict);

	// use function to write stream
	OStringStream os(is.format());
	(*function)(os, parentDict);

	// get the entry from this stream
	IStringStream resultStream(os.str());
	entry.read(parentDict, resultStream);

	return true;
}


bool Foam::functionEntries::codeStream::execute
(
	dictionary& parentDict,
	Istream& is
)
{
	Info<< "Using #codeStream at line " << is.lineNumber()
		<< " in file " <<  parentDict.name() << endl;

	dynamicCode::checkSecurity
	(
		"functionEntries::codeStream::execute(..)",
		parentDict
	);

	// get code dictionary
	// must reference parent for stringOps::expand to work nicely
	dictionary codeDict("#codeStream", parentDict, is);

	streamingFunctionType function = getFunction(parentDict, codeDict);

	// use function to write stream
	OStringStream os(is.format());
	(*function)(os, parentDict);

	// get the entry from this stream
	IStringStream resultStream(os.str());
	parentDict.read(resultStream);

	return true;
}


// ************************************************************************* //
